C / C++ / MFC

Re: c++ algorithm to find point inside polygon or not

26-Mar-08 5:04

Hi,

I am looking for algorithm which will find the given point is inside of a given polygon(a triangle) or not.
Which will work for coordinate in -ve and +ve direction.

Best Regards,
Suman

BadKarma26-Mar-08 5:53

BadKarma

26-Mar-08 5:53

If you can walk over the lines polygon you should find the point always on the same side either left or right.

Otherwise check out this page[^]

codito ergo sum

Re: c++ algorithm to find point inside polygon or not

CPallini26-Mar-08 5:55

CPallini

26-Mar-08 5:55

You don't like PtInRegion and CreatePolyRegion functions, do you?

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Re: c++ algorithm to find point inside polygon or not

SandipG 26-Mar-08 11:18

SandipG

26-Mar-08 11:18

Re: c++ algorithm to find point inside polygon or not

BadKarma26-Mar-08 21:31

BadKarma

26-Mar-08 21:31

The OP did ask for algorithms and not the functions Poke tongue | ;-P

Maybe i should redirected him, my bad $Shucks | :-\$

To be honest I didn't think of those functions. It has been a long time since I did some GUI stuff.
So thanks for the BrainRefresh Big Grin | :-D

codito ergo sum

Re: c++ algorithm to find point inside polygon or not

rp_suman26-Mar-08 21:49

Re: c++ algorithm to find point inside polygon or not

26-Mar-08 21:49

Hi,

Thanks for help..

How to create the region when the points are not in order and we need to fill the complete region by connecting outermost points using CreatePolyRegion()?

Thanks,
Suman

CPallini26-Mar-08 22:18

CPallini

26-Mar-08 22:18

Aren't you able to order the points? Is the polygon convex?
Try also the Graphics forum [^].

Re: c++ algorithm to find point inside polygon or not

rp_suman26-Mar-08 22:47

Re: c++ algorithm to find point inside polygon or not

26-Mar-08 22:47

CPallini wrote:
Is the polygon convex?

The polygon can be of any type.
The points may not be in order most of the time.

I will post in Graphics section

Thanks for help!!

Best Regards,
Suman

Saurabh.Garg27-Mar-08 0:02

Saurabh.Garg

27-Mar-08 0:02

You need Convex Hull of points to find a polygon including all points.

-Saurabh

Re: c++ algorithm to find point inside polygon or not

rp_suman2-Apr-08 21:55

2-Apr-08 21:55

Saurabh.Garg wrote:
You need Convex Hull of points to find a polygon including all points.

Hi,

Thanks for the help.

Is there function to get convex hull of points from set of polygon points which is not in order.

Thanks,
Suman

--
"Programming is an art that fights back!"

msflexgrid pointer

_chew26-Mar-08 4:31

26-Mar-08 4:31

hi guys. just started with visual c++ mfc. im currently making an SDI app with two splitters. 1 vertical and 1 horizontal. i used the SDI (windows explorer) wizard but added one horizontal splitter. leftview is a treeview control, lower right is listview control. for the upper right, the msflexgrid control. i used the "add to project-components and controls-registered activex comps" for the flexgrid. how can i obtain a pointer to my flexgrid (for manipulation)? like when i'll click on a tree node, i want to do something with my flexgrid.

any help will much be appreciated. and sorry for my english...thanks.

Re: msflexgrid pointer

rp_suman26-Mar-08 4:44

26-Mar-08 4:44

Hi,

Hope this will be helpful: Using the Flexgrid in VC++[^]

Best Regards,
Suman

Re: msflexgrid pointer

_chew26-Mar-08 5:02

26-Mar-08 5:02

thanks Suman. but i think its only applicable to dialog based apps, im not sure. i dont have a form where i could put/draw/drag the flexgrid control to, since its SDI.

regards,
_chew

Re: msflexgrid pointer

rp_suman26-Mar-08 5:18

26-Mar-08 5:18

Hi,

How you are creating flxgrid in your application?
Are you creating in runtime?

Depending on that method we will try to get pointer.

Thanks,
Suman

_chew26-Mar-08 6:05

26-Mar-08 6:05

Now I've got a problem. I've got an assertion error...

If i'll ignore the assertion message, the app will continue to load showing only two columns and two rows in the flexgrid area.

What i did was i added a class that inherits CMSFlexGrid.
This is the overriden function:

BOOL CGrid::PreCreateWindow(CREATESTRUCT &cs)
{
return CMSFlexGrid::PreCreateWindow(cs);
}

I tried to follow the ways the treeview and listview ctrls are attached to the other panes of my app. Im just confused why flexgrid could not be drawn in the upper right pane.

Thanks,
_chew

rp_suman26-Mar-08 14:58

26-Mar-08 14:58

Hi,

Check if you can use CreateControl()[^]

Best Regards,
Suman

_chew26-Mar-08 20:16

26-Mar-08 20:16

Hey, I found a very wonderful editable GridCtrl from codeproject by Chris Maunder. It works fine with my app. I already have a treeview in the left portion, a listview on the bottom right and the grid control on the upper right. during OnCreate, i was able to add column headers to the three panes. still, my old problem exists. i cant obtain a grid control pointer from the treeview side. like when i'll click a tree node, i'll modify the grid control control.

there are many tips and tricks on the net but nothing works for me.
any idea?

rp_suman26-Mar-08 22:41